A 13-year-old boy developed fever and right leg pain, and multiple acupunctures were done on legs, then visited our ER for high fever, chill and painful swellings in both legs. Bone scan showed multiple hot spots on both distal femur, both proximal tibia, and left distal tibia. MRI revealed subperiosteal abscess in right proximal and left distal tibia and signal changes without abscess in other hot spot sites on bone scan. Surgical drainage of subperiosteal abscess and curettage were performed in the right proximal and the left distal tibia. Percutaneous drillings were done to other hot spot sites. All the lesions were cured after combined antibiotic chemotherapy. Multifocal osteomyelitis in a rapidly growing adolescent has been reported not rarely. It seemed that more attentions should be paid to the possibility of multifocal acute osteomyelitis in an adolescent